Dean Jones says:

"Very well.  If you do not wish to teach 50% more students in each of your three summer sessions, what do you propose that seems fair?"

Your response:

1.  How about I teach 5% more?   Surely, if demand for these courses is high, you can find an adjunct instructor to teach one section during the summer.

2. Recall that I am already on a summer "curriculum revision task force," I'll be recruiting when I attend summer conferences, and I'm supposed to develop an Executive Education program.